The present invention relates to an improved flow regulation device, which has particularly utility in fluid operated tools.
Fluid operated tools are known in the art. For example, U.S. Pat. No. 5,005,447 to Junkers; U.S. Pat. No. 5,140,874 to Junkers; U.S. Pat. No. 5,499,558 to Junkers; and U.S. Pat. No. 5,924,340 to Junkers; and U.S. Reissue Pat. No. 33,951 illustrate known fluid operated tools. In these tools, hydraulic fluid or oil is typically used as the operating fluid.
With the employment of hydraulics to generate forces to perform work, over-travel can occur that potentially causes damage to the tool, thus limiting tool longevity. In the case of hydraulic torque wrenches, the piston being driven by oil pressure will translate the forces from the oil build up of pressure against the ratchet via the drive pawl, thus creating high torque levels to break nuts free. When the holding torque is overcome, the nut breaks free. This allows the piston still being driven by high oil pressure to lunge forward. Due to internal space limitations, the piston will then collide with the inside surface of the tool, e.g. shroud or housing, thus potentially causing damage to the piston head and/or the housing or shroud.